[PATCH 6.15 136/480] m68k: Dont unregister boot console needlessly
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2025-08-12 19:09:22
Also in:
linux-patches
Subsystem:
m68k architecture, the rest · Maintainers:
Geert Uytterhoeven, Linus Torvalds
6.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Finn Thain <fthain@linux-m68k.org>
[ Upstream commit 83f672a7f69ec38b1bbb27221e342937f68c11c7 ]
When MACH_IS_MVME147, the boot console calls mvme147_scc_write() to
generate console output. That will continue to work even after
debug_cons_nputs() becomes unavailable so there's no need to
unregister the boot console.
Take the opportunity to remove a repeated MACH_IS_* test. Use the
actual .write method (instead of a wrapper) and test that pointer
instead. This means adding an unused parameter to debug_cons_nputs() for
consistency with the struct console API.
early_printk.c is only built when CONFIG_EARLY_PRINTK=y. As of late,
head.S is only built when CONFIG_MMU_MOTOROLA=y. So let the former symbol
depend on the latter, to obviate some ifdef conditionals.
Cc: Daniel Palmer <redacted>
Fixes: 077b33b9e283 ("m68k: mvme147: Reinstate early console")
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/d1d4328e5aa9a87bd8352529ce62b767731c0530.1743467205.git.fthain@linux-m68k.org (local)
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/m68k/Kconfig.debug | 2 +-
arch/m68k/kernel/early_printk.c | 42 +++++++++++----------------------
arch/m68k/kernel/head.S | 8 +++----
3 files changed, 19 insertions(+), 33 deletions(-)
diff --git a/arch/m68k/Kconfig.debug b/arch/m68k/Kconfig.debug
index 30638a6e8edc..d036f903864c 100644
--- a/arch/m68k/Kconfig.debug
+++ b/arch/m68k/Kconfig.debug@@ -10,7 +10,7 @@ config BOOTPARAM_STRING config EARLY_PRINTK bool "Early printk" - depends on !(SUN3 || M68000 || COLDFIRE) + depends on MMU_MOTOROLA help Write kernel log output directly to a serial port. Where implemented, output goes to the framebuffer as well.
diff --git a/arch/m68k/kernel/early_printk.c b/arch/m68k/kernel/early_printk.c
index f11ef9f1f56f..521cbb8a150c 100644
--- a/arch/m68k/kernel/early_printk.c
+++ b/arch/m68k/kernel/early_printk.c@@ -16,25 +16,10 @@ #include "../mvme147/mvme147.h" #include "../mvme16x/mvme16x.h" -asmlinkage void __init debug_cons_nputs(const char *s, unsigned n); - -static void __ref debug_cons_write(struct console *c, - const char *s, unsigned n) -{ -#if !(defined(CONFIG_SUN3) || defined(CONFIG_M68000) || \ - defined(CONFIG_COLDFIRE)) - if (MACH_IS_MVME147) - mvme147_scc_write(c, s, n); - else if (MACH_IS_MVME16x) - mvme16x_cons_write(c, s, n); - else - debug_cons_nputs(s, n); -#endif -} +asmlinkage void __init debug_cons_nputs(struct console *c, const char *s, unsigned int n); static struct console early_console_instance = { .name = "debug", - .write = debug_cons_write, .flags = CON_PRINTBUFFER | CON_BOOT, .index = -1 };
@@ -44,6 +29,12 @@ static int __init setup_early_printk(char *buf) if (early_console || buf) return 0; + if (MACH_IS_MVME147) + early_console_instance.write = mvme147_scc_write; + else if (MACH_IS_MVME16x) + early_console_instance.write = mvme16x_cons_write; + else + early_console_instance.write = debug_cons_nputs; early_console = &early_console_instance; register_console(early_console);
@@ -51,20 +42,15 @@ static int __init setup_early_printk(char *buf) } early_param("earlyprintk", setup_early_printk); -/* - * debug_cons_nputs() defined in arch/m68k/kernel/head.S cannot be called - * after init sections are discarded (for platforms that use it). - */ -#if !(defined(CONFIG_SUN3) || defined(CONFIG_M68000) || \ - defined(CONFIG_COLDFIRE)) - static int __init unregister_early_console(void) { - if (!early_console || MACH_IS_MVME16x) - return 0; + /* + * debug_cons_nputs() defined in arch/m68k/kernel/head.S cannot be + * called after init sections are discarded (for platforms that use it). + */ + if (early_console && early_console->write == debug_cons_nputs) + return unregister_console(early_console); - return unregister_console(early_console); + return 0; } late_initcall(unregister_early_console); - -#endif
diff --git a/arch/m68k/kernel/head.S b/arch/m68k/kernel/head.S
index 852255cf60de..ba22bc2f3d6d 100644
--- a/arch/m68k/kernel/head.S
+++ b/arch/m68k/kernel/head.S@@ -3263,8 +3263,8 @@ func_return putn * turns around and calls the internal routines. This routine * is used by the boot console. * - * The calling parameters are: - * void debug_cons_nputs(const char *str, unsigned length) + * The function signature is - + * void debug_cons_nputs(struct console *c, const char *s, unsigned int n) * * This routine does NOT understand variable arguments only * simple strings!
@@ -3273,8 +3273,8 @@ ENTRY(debug_cons_nputs) moveml %d0/%d1/%a0,%sp@- movew %sr,%sp@- ori #0x0700,%sr - movel %sp@(18),%a0 /* fetch parameter */ - movel %sp@(22),%d1 /* fetch parameter */ + movel %sp@(22),%a0 /* char *s */ + movel %sp@(26),%d1 /* unsigned int n */ jra 2f 1: #ifdef CONSOLE_DEBUG
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2.39.5